Electric-lamp socket.



PATENTED OCT. 3l, 1905.

C. P. PARNELL.

ELECTRIC LAMP SOCKET.

APPLICATION FLBD MAY 18,1904.

5mm/wrox MC il@ UNITED sTATEs PATENT oEFicE.

CHARLES P. PARNELL, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO HARRISM. FLETCHER, OF NEW YORK, N. Y.

ELECTRIC-'LAMP SOCKET.

Specification of Letters Patent.

Patented Oct. 31, 1905.

Application filed May 18, 1904:. Serial No. 208.535.

To @ZZ whom t may concern.-

Be it known that I, CHARLES P. PARNELL, a citizen of the United States,and a resident of NewV Brighton, Staten Island, borough and county ofRichmond, city and State of New York, have invented a new and usefulImprovement in Electric-Lamp Sockets, of which the following is aspecification, reference being had to the accompanying drawings, inwhich- Figure l illustrates avertical sectional view, certain partsbeing shown in elevation. Fig. 2 illustrates a plan view on the line 2 2of Fig. 1, the outer metallic shell being removed. Fig. 3 illustrates asectional view of a fixed or so-called wall-socket embodying theinvention.

My invention is applicable to electric-lamp sockets generally; butcertain phases of it have special reference to so-called marinelamp-sockets-in Aother words, those used in places or undercircumstances where they are subjected to considerable jar or vibration,whereby the lamp is apt to become loose and to turn back in thesocket-as, for example, aboard ship, on railroad cars, in factorieswhere rapid-running machinery is employed, on automobiles, and the like.

In the drawings, A represents the conducting-wires of a mov-able socketB as they appear on the exterior thereof. C is one of these conductorswithin the socket. It connects with the terminal D, as shown. O/ is theother conductor within the socket, and it connects with the terminal D',as shown.

E is a porcelain base-piece through which a screw Fmay extend to holdthe u pper end ofthe terminal D in place, and Gr is a similar screw,which passes through a porcelain piece H, whereby the terminal Dl isheld in position.

I is an interposed porcelain or other insulating-plate.

One end of the terminal D is provided with a cup-shaped receptacle J, inwhich a spring K is seated, the upper end of which spring engages With ahollow movable thimble L, provided, preferably, with a circular shoulderM at its lower end .and with teeth N on its upper end and adapted toslide through an opening made in the insulating-piece H. This thimble isof metallic construction and serves as the central conductor.

O is the usual metallic contact-piece for the lamp P, which threads intoa threaded sleeve Q, suitably held in place by binding-screws,

Vas shown.

R is a rubber or other insulatingring, which encrcles the inside of themetallic casing S, which metallic casing and ring project upwardly, asshown at T, somewhat beyond the upper end of the threaded metallic partO.

One side of the sliding thimble L isfiattened, as at U, Fig. 2, whichflat surface engages with the corresponding surface on the insulatingpiece or block H, as shown at V, whereby the turning or rotation of thethimble on its axis is prevented.

In Fig. 3 I show substantially the same interior construction, andtherefore the parts are lettered with the same reference-letters asbefore. Fig. 3, however, illustrates a wallmay be provided with theusual base a and protector b, Which may be made of suitable insulatingmaterial, such as rubber or porcelain, and it will be observed that theupper edge c of this protector extends beyond the upper edge of thethreaded metallic conductor Q the same as the edge T of the casing Sdoes in Fig. l.

Before describing the operation of the apparatus I will briefly refer tosome of the advantages which flow from the invention which are availedof in partin lamp-sockets generally and in part more particularly insockets liable to jar, vibration, or shock. Among the advantagespertaining to lamp-sockets generally are the following: It frequentlyhappens that an unskilled or careless person undertakes to connect alamp with a socket and in so doing is very apt to screw up the lampuntil its contact-piece O brings up against the interior terminalconductor, and instead of exercising caution at this point a furthertwist is given to the lam p, which results eitherin its fracture orindistortion of the contact-piece. Sometimes, also` if the connection isnot very good, because the contact-surfaces are not bright or clean orfor some other reason, the person ignorantly assumes that it is becausethe lamp is not screwed in far enough, and consequently appliesadditional force which results in fracture or distortion, as abovestated. Under the present invention the interior contactterminalLinstead of being a rigid, practically immovable device is supportedupon the spring K, as shown, and is adapted to slide through theporcelain piece or block H as pressure is fixture or similar immovablestructure, which IOO applied upon its upper end-by the incomingcontact-surface O of the lamp,` the spring gradually exerting more andmore resistance to its compression, thus giving continually-increasingnotice to the person introducing the spring notify him that he is doingwhat he should not do. Also a dim light, owing to the uncleanlycondition of the contact-surface, is impossible under my invention,because the teeth N, which bear against the surface of the centrallamp-conductor O will, during the revolution of the lamp, rub clean thecontact-surfaces, etfectually removing any obstruction to the freepassage of the current. Again, owing to the fact that I extend theexterior metallic shell S considerably above the upper end of theexterior contact-surface Q, of the socket, as shown at T in Fig. 1 andat c in Fig. 3, the hands or person or appliances of the user areprevented from coming in contact with the conductor Q, and this result,in the construction shown in Fig.l, is aided and made perfect by theinterposition of the insulating-ring R.

The above-stated advantages, which are availed of in sockets generally,are supplemented in the case of sockets and lamps which are subjected tojar or vibration by the fact that the teeth N on the sliding thimble orcontact-piece L, under the pressure o1 the spring K, act to retain thelamp in position and to prevent its backward turning, because, being setas shown, they, under the stress of the spring, make hard rubbing orfrictional contact with the terminal O of the lamp, acting somewhatafter the manner of a pawl or detent, so as to eii'ectually preventbackward turning of the lamp, and this operation of the parts may beregulated, as the necessities of the case shall require, by increasingor decreasing the stress or stiffness of the spring K.

It ywill be obvious to those who are Jfamiliar with this art that myinvention may be adapted to sockets provided with the ordinary key orwith the form known as the receptacle-sockets and also to lamp bases orfixtures, stationary or movable, of whatever construction they may bemade, there being a great variety of such devices now known. i l callattention, however, to the fact that no key is necessary 1n order toturn off the current before removing or inserting the lamp so far assafety to the user is concerned, because owing to the construction ofthe sockets, as above explained, the live parts are protected.

Many changes may be made in the details of the invention, as abovedescribed and illustrated, without departing from the essentialsthereof. `I therefore do not limit myself to them.

I claiml l. A lamp-socket embodying a block of insulating materialprovided with a centrally-located opening, a hollow thimble adapted toslide through the opening in the insulating material and having aiiangeon its inner end which cannot pass through said opening, whereby themovement of the thimble in one direction will be arrested, terminals forthe socket, a spring partly inclosed in the hollow of vthe thimble,whereby it is yieldingly supported, the other end of the spring restingin a cavity in the appropriate terminal.

2. A lam p-socket embodying a block of insulating material provided withacentrally-located opening, a hollow thimble adapted to slide throughthe opening in theinsulati g material and having at one end a iiangeflthe outer edge of the exposed surface of its other end a series oi'teeth adapted to engage with the contact-surface of the lamp, terminalsfor the socket, and a spring, partly inclosed in the hollow of thethimble, whereby it is yieldingly supported, the other end of the springresting in a recess in the appropriate terminal.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES P. PARNELL.

Witnesses:

SAMUEL INGBER, F. M. DoUsBAcH.

iich `will not pass through the said opening and on IOO

